Self-clinching bundling strap



July 29, 1969 R. MARIAN] SELFCLINCHING BUNDLING STRAP Filed Aug. 9. 1968 Ill/III,

INVENIOR.

MA RIANI REMO A T TORNEY United States Patent 3,457,598 SELF-CLINCHING BUNDLING STRAP Remo Mariani, Berkeley Heights, NJ., assignor to Thomas & Betts Corporation, Elizabeth, N.J., a corporation of New Jersey Filed Aug. 9, 1968, Ser. No. 751,490 Int. Cl. 365d 63/00 US. Cl. 24--16 16 Claims ABSTRACT OF THE DISCLOSURE The disclosure is directed to a self-clinching bundling strap having extremely high strength. The high strength is achieved by reinforcement of certain details of the strap head and the inclusion of a novel groove in the strap which engages with a special rib placed within the aperture of the head to prevent deformity of the head during attempted pull out of the strap in its locked condition. More particularly, a base portion coupled to the head is provided to backup the head and in addition there is provided support members, adjacent to and flanking the aperture in the head, support members being coupled both to the head and to the base member. To reinforce the head further, various arrangements of the vertically operable locking means in the head are arranged to reduce the amount of insertion force required while greatly increasing the pullout required to separate the strap from the locking means.

BACKGROUND OF THE INVENTION Field of the invention The invention is directed to the field of bundling discrete articles such as conductors into a unitary cable bundle. In a similar fashion may be used to tie together lengths of pipe, tubing, hose or similar articles which are normally found in discrete individual form and which are desired to be fastened together in a unitary bundled form.

Description of the prior art Prior art self-clinching bundling straps are shown in US. Patent No. 3,186,047, issued June 1, 1965, to Daniel P. Schwester et al., and owned by the assignee of the instant invention. The self-clinching bundling strap set forth in the cited patent consists of an elongated strap body having at a first end a tapered tail end section. Ridges, or similar devices, are provided at the tapered tail end section to facilitate the handling of the strap when the strap is being pulled through the head end portion. At the opposite end of the strap from the tail end portion is the head end portion having a transverse aperture there through for receiving the body portion of the strap once the strap has been placed about a plurality of articles to be bundled. Mounted within the aperture of the head end portion is a barb, or similar self-clinching locking device, arranged in a one-way arrangement, such that the strap may be passed through the head aperture but upon attempted withdrawal of the strap, from the head end portion, the locking device will engage the strap and prevent such pullout. The pullout strength of a selfclinching bundling strap, of the type shown in Schwester, is determined by the tensile strength of the strap itself and by the strength of the barb or locking device used to prevent withdrawal of the strap from the aperture of the head end portion, and by the resistance to deformity of the head end portion. It has been found in practice that the head end portion immediately adjacent the locking device will be deformed due to excessive application of withdrawal forces to the strap and will thus permit the barb, or locking device, to be displaced from its locking position and will allow withdrawal of the strap. Further,

3,457,598 Patented July 29, 1969 it is found that under extreme withdrawal forces applied to the strap portions the head end portion itself will deform which effectively increases the size of the aperture within the head end portion and thus permits flexure of the locking device, or barb, beyond its normal position allowing removal of the strap.

SUMMARY OF THE INVENTION The present invention seeks to overcome the difficulties noted above with respect to prior art self-clinching bundling straps of the type shown in the Schwester et al. patent cited above. Provision is made for the reinforcement of the bundling strap in all of the areas known to be weakened or deformed during the subjugation of the strap to extreme pullout forces. Pullout forces are defined as those forces which are applied to the strap to attempt to remove the strap portion from the locked engagement with the locking device, or barb, placed within the head end aperture. In order to provide the additional strength and reinforcement a base member is provided behind the head end portion to provide additional rigidity and to prevent the deforming of the head end portion. Additionally, support means, or ribs, are placed adjacent and flanking the aperture within the head end portion and coupled between the head end portion and the base member further to reinforce the head end portion and thus prevent its deforming when subjected to high pullout forces. Finally, a longitudinal groove is placed through one surface of the strap and the complementary raised rib is provided in the aperture of the head end portion for a portion thereof. When properly positioned, the groove, within the strap body will engage with this rib and the cooperation therebetween will prevent deforming of the area immediately adjacent the locking device, or barb, and thus add additional strength and increase the pullout required to separate the strap from the head end portion. It is therefore an object of this invention to provide an improved self-clinching bundling strap.

It is yet another object of this invention to provide an improved self-clinching bundling strap having a longitudinal groove in the body portion of the strap and a complementary rib within the aperture of the head end portion; said rib and groove cooperating to reinforce the head end portion beyond the locking device, or barb, and thus prevent withdrawal of the strap body.

It is still another object of this invention to provide an improved self-clinching bundling strap wherein the head end portion of such strap is greatly strengthened by the use of reinforcement ribs adjacent to the aperture of the strap head end portion.

It is still another object of this invention to provide a self-clinching bundling strap having increased pullout strength and being reinforced by the use of a base member providing additional strength and rigidity to the head end portion of said strap.

It is yet another object of this invention to provide an improved self-clinching bundling strap having increased pullout force achieved by the reinforcement of the head end portion and employing a base member and two supporting ribs placed adjacent the aperture, within the head end portion, and coupled between the head end portion and the base member to greatly increase the rigidity and prevent deformance of the head end portion during the application of extreme pullout forces.

It is still another object of this invention to provide an improved self-clinching cable bundling strap having a locking device, or barb, with decreased insertion force and increased pullout forces.

It is yet another object of this invention to provide an improved self-clinching bundling strap wherein the locking device is proportioned so as to force the strap to engage a portion of the upper surface of the aperture of the head end portion and thus prevent removal of the strap portion from the head end aperture.

Other objects and features of the invention will be pointed out in the following description and claims and illustrated in the accompanying drawings, which disclose, by way of example, the principles of the invention, and the best modes which have been contemplated for carrying them out.

BRIEF DESCRIPTION OF THE DRAWING In the drawings:

FIG. 1 is a side elevation of a cable bundling strap constructed in accordance with the concepts of the invention showing in solid lines the strap positioned about a plurality of conductors to be bundled into a cable and in dashed lines to show the strap prior to such installation.

FIG. 2 is a front elevation of a portion of the cable bundling strap of FIG. 1 showing details of the head end portion.

FIG. 3 is a top elevation of the head end portion of the strap of FIG. 1.

FIG. 4 is a section through the strap body taken along the lines 4-4 of FIG. 1.

FIG. 5 is a sectional view of a portion of the strap of FIG. 1 taken along the lines of 55 of FIG. 1.

FIG. 6 is a side elevation, partly in section, of the head end portion of a cable bundling strap as constructed in accordance With the concepts of FIG. 1.

FIG. 7 is a side elevation, partly in section, of the head end portion of a modified cable bundling strap.

FIG. 8 is a side elevation, partially in section, of the head end portion of an alternative embodiment of the cable bundling strap constructed in accordance with the concepts of the invention.

Similar elements will be given similar reference characters in each of the respective figures.

DESCRIPTION OF THE PREFERRED EMBODIMENT Turning now to FIG. 1 there is shown a self-clinching bundling strap 10 constructed in accordance with the concepts of the invention. Strap 10 as shown in dashed line is in its fully extended position whereas as shown in solid line it is in the position it would take when coiled about a plurality of discrete articles such as the conductors 13. Strap 10 has a body portion 12 which extends generally from the head end portion to a tail end portion. A first generally flat surface 14 exists on the first side of the strap body 12 while a second surface 16 parallel with the first contains a longitudinal groove 18 therein. The edges of the strap, between the surfaces 16 and 14, are rounded as at 20. Turning to FIG. 4 the cross section of the strap, taken along the lines 44 of FIG. 1, shows the relative shapes of the surfaces 14 and 16, the position and relative size of the longitudinal grooves 18 as well as the rounded edges 20.

The strap body portion 12 terminates at a first end in a tapered tail end section 22 which has on its surface coextensive with the surface 14 of the strap body 12, a set of raised ridges 24 which facilitate the handling of the straps during the time that the strap 10 is to be placed about a plurality of articles 13 to be bundled and is to be pulled through a head end portion to be described below. Turning to FIG. 5 a section of the tail end portion 22, taken along the lines 55 of FIG. 1, is shown. As can be seen, the surface of the tail end portion 22 coextensive with the surface 16 of strap body 12 has within it, a rather wide longitudinal groove 26 which is tapered to meet the narrower groove 18 of the main body portion 12, approximately at the joinder of tapered tail end portion 22 with the main body portion 12 of the strap. The function of the longitudinal grooves 18 and 26 will be set forth below with greater particularity.

At opposite end of the strap body 12, is a head portion 28 having a fillet 30 extending between the fiat surface 14 of the strap body 12 and the head end portion 28. Turning now to FIGS. 2, 3 and 6 details of the head end portion 28 may now be appreciated.

Head end portion 28 has a boss portion 32 having a central aperture 34 passing therethrough. The shape of the central aperture 34 is approximately that of the cross-section of the stop body 12 as shown in FIG. 4. Central aperture 34 is sufliciently large to permit easy passage of the strap of body 12 therethrough. Centrally located within the head aperture 34 is a rib 36 which as is shown in FIG. 6 extends generally from a back face 38, of the head end portion to a point approximately midway between said back face 38 and the front face 40 to the head end portion 28. The rib 36 is proportioned to fit within the longitudinal groove 18 of the strap body 12. Coextensive with the surface 16, of the strap body 12, is a base member 42 which extends entirely around the boss 32. Also coupled between the boss 32 and the base 42 are two support members 44. The base member 42 and the support members 44 provide additional rigidity to the boss 32 as will be described below. Extending from the top of the boss 32 and communicating with the central aperture 32 is a slot 46. Slot 46 is provided to aid in the assembly of the metallic tongue which is employed as a locking device as will be described below. Further, communicating with the central aperture 34 and extending down to, but not through, the bottom portion of the boss 32 is a further slot 48.

It has been found in practice, the slot 46 and the slot 48 are necessary in order to assemble the metallic tongue which will be employed to lock the strap body portion 12 in such a manner that it may not be withdrawn from the head end portion 28. The presence of the slots 46 and 48 produce some weakening of the boss 32. Thus under extreme tension applied to the strap body portion 12 to withdraw it from the head end portion 28, fiexure of the relative halves of the boss 32 occur which increase the size of the central aperture 34 thereby allowing the strap body portion 12 to be withdrawn. The presence of the base member 42 and supporting members 44 provide extra firmness to the head end portion 28 and prevent fiexure of the relative portions of the boss 32 and thereby eliminate the increase in the size of the central aperture 34 which would permit pullout of the strap body portion 12.

Turning now to FIG. 6 the details of the metallic tongue used as a locking device to prevent the unwanted withdrawal of the strap body portion 12 from the head end portion 28 is shown. As is shown in FIG. 1, once the tail end portion has been Wrapped around the plurality of articles such as the conductors 13 and inserted through the head end portion 28, the strap body portion 12 will be drawn up as tightly as can be about the atricles 13 to hold them in the desired bundled position. At this time the strap body portion will be permitted to selectively deflect the metallic tongue 50 in the direction to permit the strap body portion 12 to be drawn tightly about articles 13. Metallic tongue 50 has a knife edge 52 arranged to engage with and bite into material of the strap body 12, on attempted withdrawal of the strap 12 from the aperture 34. The metallic tongue 50 is caused to deflect in a direction toward the back surface 38 of the head end portion and will lockably engage itself into and with the body portion 12 of the strap. The flexible, metallic tongue 50 is formed of a unitary piece of material such as stainless steel, or the like, which has great flexibility and strength. It is bent about a central line 54 to define a first area 56 extending between the line 54 and a knife edge 58 and a second portion 60 between the line 54 and the knife edge 52. The first portion, that is between the line 54 and the knife edge 56 will be placed within the material of the head end portion 28 to anchor itself thereto. The remaining portion 60 will be free to flex with the insertion of the strap body portion 12 and its attempted withdrawal. The metallic tongue 50 is positioned so that the area 56, bites into the material of the head end portion 28 at the meeting of the surfaces 62 and 64 which define the cavity 66 extending from the slot 48 back towards the rear face 38. In the position, shown in FIG. 6, the area 60 of the metallic tongue 50 will be mounted at an acute angle to the surface 64 of the cavity 66. Due to this mounting, the insertion of the tail end portion 22 of the strap through the rear face 38 of the head end portion 28 into the aperture 34 will permit the portion 60 of the tongue 50 to deflect toward the front face 40 and provide a minimum amount of interference with the strap 10 and permit it to pass through the aperture 34. The large longitudinal groove 26, of the tail end portion 22, will clear the knife edge 52 of the metallic tongue 50 and it will not interfere with the passage of the tail end portion therethrough. However, any attempt to remove the strap 'body portion 12 from the head end portion 28 by pulling on the strap 10 itself, will cause the rotation of the metallic tongue 50 in a direction towards the rear face 38 of the head end portion 28 and will cause it to be wedged against the upper surface of the aperture 34 and will also cause the knife edge 52, of the metallic tongue 50, to bite into and grasp the material of the strap 12.

It has been found in the past that the material generally between the surface 62 of the cavity 66 and the rear edge 38 of the head end portion 28 under excessive load will be deformed and thus will allow the metallic tongue 50 to swing entirely in an arc towards the rear face 38 of the head end member 28 and thus will permit the strap body 12 to be withdrawn from the head end 28. The presence of the rib 36, in engagement with the longitudinal groove 18, prevents this however. The strap body 12 acts as a support for the material between the surface 62 and the rear face 38 of the head member 28 and thus prevents deformance of this particular area.

As an alternative to the mounting of the tongue 50 in the manner shown in FIG. 6, the entire tongue 50 may be turned through an arc of 180 and positioned at the intersection of surfaces 62 and 64 of cavity 66, as shown in FIG. 7. Such a manner of mounting of the tongue 50, still facilitates the easy insertion of the strap body 12 into the head end portion 28 and gives the increased pullout forces required. This arrangement permits area 56 of tongue 50 to be inserted directly from slot 48.

Turning now to FIG. 8 there is shown a further manner of providing a flexible metallic tongue which greatly maximizes the pullout forces to dislodge the strap- 12 from the head end portion 28. This involves the use of a metallic tongue 70 having an area 72 greater in length than the area 60 of the metallic tongue 50 of FIG. 6.

In this arrangement, the attempt to deflect the metallic tongue 70 will cause it to jam the strap portion 12 into contact with the upper surface of the aperture 34 so that it cannot be withdrawn. In extreme cases the tongue 70 may cut through the strap body portion 12 and enter the upper surface of the aperture 34 to prevent withdrawal of the strap body 12 from the head end portion 28.

While there have been shown and described and pointed out the fundamental novel features of the invention as described in the preferred embodiments, it will be understood that various omissions and substitutions and changes of the form and details of the devices illustrated and in their operation may be made by those skilled in the art, without departing from the spirit of the invention.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A high strength article handling strap comprising: an elongated strap portion having two generally flat surfaces; there being a first groove extending substantially the entire length of said strap portion on a first of said flat surfaces; said strap portion terminating at a first end in a tapered tail end; said tapered tail end having ridges on said second flat surface of said strap portion; said strap portion terminating at its second end in a head member having an aperture extending therethrough from a first face to a second face thereof transverse to said strap portion for receiving said strap portion therein; a rib in said head member aperture extending substantially from said first face for a portion of said head member; said rib engaging said first groove when said strap portion is placed in said head aperture; and selectively operable locking means positioned in said head aperture adjacent said rib, said locking means permitting insertion of said strap portion within said head aperture and preventing withdrawal by lockably engaging said strap portion.

2. A strap, as defined in claim 1, wherein said tapered tail end has a second groove in said first flat surface communicating with said first groove; said second groove being proportioned to pass without engagement said selectively operable locking means.

3. A strap, as defined in claim 1, further comprising a base member having an aperture therethrough coupled to said head member; said apertures in said head member and said base member being in alignment.

4. A strap, as defined in claim 3, further comprising first and second support members respectively coupled to said head member and said base member adjacent said head aperture and extending along the line of said strap portion.

5. A strap, as defined in claim 1, further comprising a base member having an aperture therethrough coupled to said head member and coextensive with said second flat surface of said strap portion; said apertures in said head member and said base member being in alignment.

6. A strap, as defined in claim 5, further comprising first and second support members respectively coupled to said head member and said base member adjacent said head aperture and extending along the line of said strap portion.

7. A strap, as defined in claim 1, further comprising first and second support members respectively coupled to said head member adjacent said head aperture and extend ing along the line of said strap portion.

8. A strap, as defined in claim 1, further comprising a first slot in said second face of said head member extending from the top of said head member into said head aperture and a second slot in said second face of said head member extending from said head aperture towards the bottom of said head member; the junction of said head aperture and said second slot forming a cavity.

9. A strap, as defined in claim 1, further comprising a cavity below said head aperture and communicating therewith.

10. A strap, as defined in claim 9, wherein said cavity has a bottom surface substantially parallel with the top surface of said head aperture and a back surface inclined with respect to the top surface of said head aperture and the bottom surface of said cavity.

11. A strap, as defined in claim 10, wherein said selectively operable locking means is a tongue having a sharpened first free edge and a second opposite edge mounted adjacent the joinder of said bottom and back surfaces of said cavity.

12. A strap, as defined in claim 11, wherein said tongue is metallic and is deformed about a line intermediate its first and second edges; a first portion of said tongue between said line and said second edge being embedded in said head member and the second portion of said tongue between said line and said first edge extending into said head aperture at an acute angle with respect to said cavity bottom surface.

13. A strap, as defined in claim 11, wherein said selectively operable locking means is a metallic tongue proportioned such that any attempt to withdraw said strap portion from said head aperture causes said first free end to engage the top surface of said head aperture.

14. A strap, as defined in claim 1, wherein said selectively operable locking means is a tongue extending from said head member into said head aperture; said tongue 7 8 extending at an acute angle to the upper surface of said flat surface of said strap portion is arranged to receive head aperture. indicia thereon.

15. A strap, as defined in claim 1, wherein said selec- References Cited tively operable locking means is a tongue extending from said head member into said head aperture; said tongue 5 UNITED STATES PATENTS extending at an acute angle to the upper surface of said 3,009,220 11/1961 Fein. head aperture and proportioned such that any attempt 3,049,771 8/ 1962 Litwin et a1. 24-73] to remove said strap portion from said head aperture ,1 9/ 1964 Logancauses the free end of said tongue to engage the upper 3,258,319 7/ 1966 Weckessersurface of said head aperture. 10

16. A strap, as defined in claim 1, wherein said second DONALD GRIFFIN- Primary EXaminel 

